Parallel resurfacing



Dec. 29, 1931. A. KADOW ET AL 1,838,553

PARALLEL RESURFAC I NG Original Filed Aug. 1 1925 2 Sheets-Sheet l Patented Dec. 29, 1931 UNITED-STATES,PATENT oer-1c]: a

AUGUST KADow AND DAVID c. SMITH, or TOLEDO, oHIo,AssIeNoRs, BY nIREcrAND MESNE Assmnmnntrs, TO ownns rrnmors GLASS COMPANY, A CORPORATION or OHIO PARALLEL RESURFACING I Application fired August 17, 1925, Serial No. 5o,69 0."ne ewed April 10, 1928.

Our invention relates to surfacing machines and more particularly to machines for grinding and polishing sheet or plate glass.

An object of the invention is to provide imli proved means for applying and distributing the pressure of the grinder; orgrindin'g surface on the surface of the work-piece in a manner to avoid excessive pressure at any one point and thereby avoid chipping or'breale 10 ing of the work-piece. With grinding machines in common'use atthe present day, con s'iderable difliculty is experienced on account of chipping or breakingof the work-piece and particularlythe corners thereof. The application of pressure on the work-piece by the grinder as it rotates, is often concentrated at one point on the surface of the work-piece, frequently at a cornerpresulting frequently in chipping or breaking of the work-piece. In the present invention, this difliculty is overcome by providing adequate means for distributing the pressure of the grinder and for causing it automatically, during 1ts rotation, to maintain a proper adjustment to the surface'of the work-piece. j V

The invention further provides suitable means for adjusting the pressure so that it is comparatively light when the danger of breakage is greatest and may be gradually increased asthe work progresses.

A further object of the'invention is to provide' a grinding mechanism which will operate automatically to reduce the thickest portion of the work-piece most rapidly, thereby tending to reduceit to 'a uniform thickness throughout, while at the same time providing for proper distribution of the pressure to avoid excessive presure at any point on the surface of the work-piece. r

To this end, the work-piece and grinding plate are horizontally disposed and the grinding plate has a universal joint connection witha vertical drive shaft, permitting the plate as it rotates, to tilt in any direction necessary to maintain a proper distribution of the p'ressureto difi'erent'points on the surface of the work-piece. V

Owing to the rapidrotation of the grinding plate,'there is always a tendency for it to assume a position perpendicular to theaxis of rotation, that is,'a horizontal position, so that the pressure is greatest on the highest sideor. portion of thework-piece. The grinding action is, therefore, always concentrated on the higher'or thicker portion of-the work-piece,"

thus tending to a reduction to uniform thickness. 1

A further feature ofthe invention relates to the provision of improved means for conveying' and distributing to the surfaces ofthe Work-piece, the ab-rading and polishing ma terials which are ordinarily heldin suspen sionin'a 1i uidL. if I 1 a Other objects of the invention will appear hereinafter.

Referring tothe drawings: V

Fig. l'is a side elevation of an embodiment of. the invention in a surfacing machine forglass plates; Y

Fig.2 is avertical'section through the apparatus of Fig.1; and r Fig; 3 isa plan of the plate holder andsupport ofthe apparatusof Fig. 1;. 7 Motor 1 is shown as having shaft' 2 effective through gearing 3 for driving pulley 4 about which extends belt 5 over idler pulley 6 adjacent idler pulley 7. Adjacent the pulley at is idler pulley 8; Thishelt 5 is provided with reaches from the pulleys 6, 7, for rotat-- ing pulley 9, and reaches from the pulleys 4, 8, foractuating approximately coaxial pulley 10 in an opposite direction from the rotation of the pulley 9. Base" 11 is provided with uprights 12 assembled therewith by bolts 13 near one 'side, and at the opposite side uprights "14 assembled withthe base 11' by bolts 13; Centrally this base 11 is provided with bearing 15 for tubular shaft 16 upon which the pulley 1O ismounted. Ad ditionally, guide bearing 17 is provided for the upperportion of this shaft 16. This guide bearingl'? provides cover plate 18 partially housing, with upwardly extending flange 19, the pulleylO. Openings 20 through this flange "19 belt 5. V a

Sustained by this guide bearing 17 is sup v port or lowerv table 21 fast with the tubular shaft 16 for. rotation therewith. Disposed clear of this table 21 is frame or holder 22 provides Ways for the driving having seat or opening 23therein in which may be loosely disposed a plate or sheet 24 of the material to be acted upon, said plate 24, as of glass, protruding through this opening 23 to be supported upon the rotary table 21 below the frame 22. and also extending above this frame 22 tobe engaged by opposing upper table or loading device 25.

The frame 22 extends to be guided by ways 26 carried, by the respective uprights 12, 14, in a common plane. Upwardly extending from the base 11 are columns 27, 28. Supplemental frame 29 is mounted on the column 27 and has connection by hinge 30 and clamp ing bolt 31 with the column 28. This frame 29 provides bearings 32, 33, for shaft 34 ap proximately in alignment with the shaft 16. Splinedon this shaft 34-is the pulley 9. This shaft; 34 at. its lower ter1ninus,.is provided with spherical portion 35 coacting withseat portion 36 of the table Bolts 37 mount supplemental seat portion 38 for assembling.

this spherical portion 35 as a rocking hearing withthe table-25. There is a recess 39 inthe-seat 36 with which keying pin 40, protruding from the spherical portion 35, may engage thereby holding the table 25 for. rotation with the shaft 34 while still. allowing freedomifor self-adjustment of; the table 25 and plate 24 slightly out of the plane perpendicular to the axis of. the shaft 34.

From the frame 29 upwardly extends auxiliary bracket 41 providing fulcrum 42 for lever 43 carrying pin 44 coacting withextension 45 effective through anti-friction bearing 46 in cap 47 in applying the-load on the shaft 34. This load is mounted: on the long arm of this lever 43 .by depending rod 48 carrying weight 49. This rod 48 is adjustable to various seat positions 50 in the lever 43 for varying the loadingaction of the table 25 as resting upon the plate 24;.

From gearing 3 extends driving belt 51. topulley 52 on shaft 53 as upwardly extending andcarrying disk 54 having crankrpin- 55 coacting with slot 56 in the holder or frame 22..

The holder 22. with the work-piece 24 therein is therefore reciprocated. while the supporting table 21 andthe loading table 25 are rotating simultaneously in opposite di-- rections. This insures the traverse of the relative actions upon the plate 24 with a dressing operation occurring. simultaneously upon the opposite sides of the plates toapproximate parallel resurfacing in a dressing whether it be grinding or polishing or other resurfacing. The speed of operation ispreferably above 150 R. P. M. in closed circle or orbital actions. The speed is such that the load applying table 25 may accommodate itselfto the face of the work due to the rocking joint connection with its driving shaft 34. At the speed of operation, there is a tendency for adjusting: as to unevennessin the plate with an insured excessive action pon the extreme out-of-plane portions as projecting, independently of severe strain upon the structure.

It will thus be seen that the universal joint connection between the driving shaft 34 and the surfacing element or grinder 25 performs two definite functions. In the first place, it permits universal tilting movement of the grinder relative to the drive shaft, sufficient to accommodate the grinder to any projections or unevenness of the surface of the work-piece, thereby distributing the pressure and avoidingexcessive pressure or strain at any particular point which would result in chipping orbreaking of the work-piece. In the second place, owing'to the-weight. of the surfacingelement orgrinder anditsrapid rotation about the vertical axis of the drive shaft 34, thereis atendency for it. always to maintain a horizontalposition, or, in other words, for itsaxis of rotation to assume a vertical direction and position. coinciding with the axis of the drive shaft 34. As a result, the pressure of. the grinder on the highest point of contact with thework-pieee is always considerably greater than at other points,.so that the highest pointsor portions of the .work surface-are ground down most rapidly. The grinding action, therefore, always tends toward reduction of the workpiece to a uniform thickness.

In practice the opening 23 in the frame 22 may be preferably for-asingle plate, and approximately the size of said plate so that the frame is effective indefinitely controlling all shifting. of the plate relatively to the opposing tables.

In conducting these dressing operations, it is desirable that a flushing occur with-an adhesive or-polishing medium. Tothis end. upper table 25 isprovided with an annular flange fi'z', thus providing an annular reservoir 53into which the-emery grit in suspension, the tripoli, or the rouge, may be poured 0 flow by duct 59 into position centrally of the; plate 24 there to be distributed by radially extending grooves or ducts 60 formed in the lower surfaceof the table 25'. Reservoir 61. (Fig. 1) above the plane of the supporting table 21 has duct 62 therefrom connected by gland 63 with tubular way 64in the shaft 16 to connect with opening 65 inthe table 21. from which extendradial grooves or ducts 66 formed in the upper surfaceof the table 21 below theplate 24. Accordingly, in the operation of this machine, there is a maintained supply of the material. in-suspcnsion in aid of the grinding or dressing operations. As a plate is dressed down to the parallcl planes, or. desiredthickness, switch 67 (Fig. 3) may be operated to shut off the motor 1. The bolt 31 may be run backto permit swinging. of the-hinge 30 inopening the clamp so that. the auxiliary frame 29 may be swung upon the column 27 to have the table 25 clear of the frame 22 thus permitting access to such frame for removal of the dressed sheet or plate 24 and substitution of a subsequent sheet for a repetition of this cycle 7 V of operations by again throwing-in the switch 67 after the auxiliary frame 29 has been reassembled to have the table 25 in position over this new piece of work. The dressing composition fort-he upper side of the work is supplied from the reservoir 61 by ducts 68 to the reservoir 58. The distributing grooves in the tables 21, 25 are similar.

The apparatus of this disclosure may be designed to handle readily different thickness of finished plate. To this end, theframe or holder 22 may have its position as to the lower table 21 adjusted by set screws 69 acting upon the guides 26.

It is to be noted in the operation of'the dressing or treating machine of this disclosure, that the material acted upon is preferably entirely covered at all times by the abrading or active surfaces. This is a factor against plate fracture. The plate irregularities are neutralized as to reflecting back upon the machine, due to the rocking joint mounting for the upper table. The adjustment of the loading of this upper table or device may be advantageously adopted for slight pressure application as the dressed area is small, with increase of the loading as the area builds up, thus to reduce plate disturbance tendencies with the resulting increase in merchantable product. c

What is claimed and it is desired to secure by United States Letters Patent is:

In a machine for grinding and polishing sheet or plate glass, the combination of a work holder consisting of a thin sheet of flat material of less thickness than the work-sheet, said work holder having a rectangular opening to receive a correspondingly shaped Workpiece, horizontally dis osed stationary guides arranged to receive t e edges of the work holder and hold the latter in a horizontal po sition, grinding plates above and below the work-piece, a motor, driving connections between the motor and said plates for rotating them simultaneously in opposite directions for simultaneously grinding the upper and lower surfaces of the work-piece, and automatic means operated by the motor for reciprocating the work holder and work-piece during the grinding operation, said grinding surfaces being of suflicient extent and arranged to substantially cover the entireupper and lower surfaces of the work-piece throughout the grinding operation.

In witness whereof we aflix our signatures.

AUGUST KADOW.

DAVID C. SMITH. 

